nitrous oxide (N2O)

Nitrous oxide (N2O), also known as dinitrogen oxide or laughing gas, is a colorless gas with a sweet smell that is sometimes used as an anesthetic or analgesic during surgical or dental operations, and an aerosol propellant. Nitrous oxide is soluble in water, ethanol, and sulfuric acid. On heating above 520°C, it is decomposed to nitrogen and oxygen and will thus support the combustion of many compounds. It is, however, relatively unreactive, being inert to halogens and alkali metals.


Nitrous can be prepared by cautiously heating a mixture of ammonium sulfate and sodium nitrate. By a double decomposition reaction sodium sulfate and ammonium nitrate are formed. The latter compound then decomposes to yield nitrous oxide and water. The gas is often collected over warm water as it is soluble in cold.


density 1.97 g dm-3
melting point -90.8 °C
boiling point -88.5 °C